Thread: Biodiesel and engine lubrication.....

very interesting, but as always there is a fair element of vested interest in there...

The part I can't get my head around is how some motor companies can approve B100 for most/all motors, others are so conservative to only approve some motors for B5! It does my head in because there is hardly any info on how these decisions are reached by the industry or specific company in question... we hear lots about "higher pressure injectors don't like Bio", some info about low pressure injectors coping better etc etc...

what we need is an oil company to bring out bio-diesel specific motor oils with the proper blend of oxidation inhibitors added for the given Bio blend (e.g. B5-20, B20-50, B50-80, B80-100). this solves all the "problems" from an oil perspective, but unfortunately doesn't change the injector/injector pump life cycle question...

On the flip side, what I have read is that bio has significantly better lubricity properties than diesel, especially low-sulpher.

sorry but Im going to call that slightly missleading, and considering its been published on the dollar of 3 major oil companies Im not surprised...


there are some facts that are slightly mis-represented and unless you carefully read the whole thing you'll miss the disclaimers....

one example is a section that mentions along the lines that biodiesel will cause additional engine wear, and then under it is a photo of the crank end of a block with a rod (presumabley attched to the piston still in the bore) and a hand with some crud held as proof, under that is a statement that without changes in the maintenance schedule and the lubricants engine damage may occour. Call me pedantic but if I put 5-15 wt high altitude winter grade oil in a diesel engine operated it at the heights of the blue mountains in winter then drove it to darwin and worked it during the wet season without changing my maintenance schedule and lubricants I'd get the same damage.

there are however some points that are obscurely mentioned but not signifiacantly highlighted namely the quality of the bio that you use makes the most difference and there is very little mentioned about the generational differences in metalurgy and injection techniques/pressures that will change the way that using bio will effect the wear rates of your engine.

Originally Posted by Slunnie

On the flip side, what I have read is that bio has significantly better lubricity properties than diesel, especially low-sulpher.

as bio is an ester it does have better lubricity, but that only helps on the pump/injector side.
What they are talking about in these article is what happens when the bio mixes with a conventionally additised oil in the crankcase, and the resultant oxidative stress incurred.

Originally Posted by Blknight.aus

<snip>
and there is very little mentioned about the generational differences in metalurgy and injection techniques/pressures that will change the way that using bio will effect the wear rates of your engine.

They used industry standard tests like the Mack EO-O and T12, Cummins ISB and Volswagen TDI tests to evaluate the effects.

The bottom line is that regardless of the engines metalurgy and injection type, the oxidative stress on the oil induced by fuel dilution is the same, regardless.

The other thing that I haven't mentioned is that the new ULSD fuels are showing to be pretty hard on engine oils too, according to the people I talk and listen too.

Oils that worked extremely effectively 3 or five years ago are being pushed to the limit and then some by the additives now in use when the fuel gets into the crankcase.

Storm in a tea cup......

Originally Posted by EchiDna

very interesting, but as always there is a fair element of vested interest in there...

The part I can't get my head around is how some motor companies can approve B100 for most/all motors, others are so conservative to only approve some motors for B5! It does my head in because there is hardly any info on how these decisions are reached by the industry or specific company in question... we hear lots about "higher pressure injectors don't like Bio", some info about low pressure injectors coping better etc etc...

what we need is an oil company to bring out bio-diesel specific motor oils with the proper blend of oxidation inhibitors added for the given Bio blend (e.g. B5-20, B20-50, B50-80, B80-100). this solves all the "problems" from an oil perspective, but unfortunately doesn't change the injector/injector pump life cycle question...

I'm betting the additive suppliers like Lubrizol are already formulating or have available additive packages to combat this.

The fellow that does my UOA interpreting (http://www.dysonanalysis.com/) has put me onto a HOBS ester based lube that has an amazing add package that would probably work really well with bio diesel, as some of their lubes have shown excellent results in petrol fuel dilution monsters like the new DI Audi/VW's. None of the boutique syn oils, let alone the conventional synthetic VW approved oils can last a normal oil change in some of these DI engines.